Engine ID

[philthehill]

The head should not be grit blasted as the grit can get into odd corners of the coolant galleries and is then very difficult to remove.
To check whether the head has been skimmed check the thickness of the head. It should be 2.75". Anything less and the head has been skimmed.
When you fit the head make sure that there is a gap between the by-pass stub and the water pump stub. Sometimes the bypass stub is too long and when the head is fitted the stub holds the head off the block.
Otherwise all looking good.

[rocco]

Cheers Phil, it's 2.748 give or take.

[rocco]

I popped the new valves in to the new guides in the newly cut seats today but strangely, one of the exhaust valves doesn't want to go through any of the guides. And one of the inlet valves needs to be encouraged a bit more than it should be to hit the seat.

The guy who did the head work had one of each valve and I expected that to be all that was needed. Somehow, this one exhaust valve is fatter than the others. All bought at the same time and place (ESM).

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Is the problem best overcome by sanding down the valve stem somehow or by reaming one of the guides? It must be fairly close but although the inlet valve will sit down fully if forced, the exhaust valve definitely does not.

[philthehill]

Have you measured the valve stem to determine if the valve stem is over size?
The valve stem dia should be for the exhaust 0.2788" to 0.2793"
The valve stem dia for the inlet valve should be 0.2793" to 0.2798".
There should be at least 0.0015" clearance between valve stem O.D. and valve guide I.D..
I would suggest that you ream all the valve guides to 9/32"
The guides should have been reamed after the guides had been fitted.
I would advise against sanding the valve stems.

[rocco]

I should have updated this earlier but I took the head back to the engineering place and the guy got all the valves sliding nicely for me in the end.

I've now removed the cam, followers, crank and just have the block to work on now. I'd like the mating face to be skimmed like the head was and the cam and crankshafts to be checked. One of the shells has 020 stamped on it so unless I'm mistaken, it has already been worked on in the past, most likely by Unipart when they painted it gold. Perhaps the A D stamped on the engine number plate would confirm that and signify the 2/1000th inch grind?

I'll share a couple of photos of the camshaft lobes and buckets which look to me a bit rough and may be worth sourcing new/recon parts?

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The bores feel fairly smooth and there is only a minuscule lip at the top but upon zooming in on the photos, the material looks like it's corroding/bubbling - so a bit of work here might also be needed. The crank also seems a bit rough.

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[rocco]

I've also just noticed some numbers stamped on the block. A "2" is visible but an "X" has been stamped over at least two of the "3s".

Obvious question, does anyone know why and what it means?

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[philthehill]

The camshaft and cam followers are scrap and need to be replaced. Note: the camshaft does not appear to be a standard item. With the two identification rings it could be a MG Metro item.
The numbers/figures were identification numbers/figures used in the reconditioning process.
The crankshaft needs to be measured and if within limits re-ground.

[rocco]

Thanks Phil, that's very useful to know. I suppose that if it is out of a Metro then it was installed as an upgrade along with the 1098 head.

It will go in the bin along with the followers. I'll measure the crank tonight and find out what the limit is. I guess that if it's already been ground (020) then there is at least one more to do, perhaps to 040?

Strange that the "3" marks on the block are crossed out and the "2" is still valid. Do you know what exactly it denotes? Not that it matters too much but it appears to be counting down and I wonder if it's related to the bores, the surface or the crankshaft.

[svenedin]

Thanks Phil, that's very useful to know. I suppose that if it is out of a Metro then it was installed as an upgrade along with the 1098 head.

It will go in the bin along with the followers. I'll measure the crank tonight and find out what the limit is. I guess that if it's already been ground (020) then there is at least one more to do, perhaps to 040?

Strange that the "3" marks on the block are crossed out and the "2" is still valid. Do you know what exactly it denotes? Not that it matters too much but it appears to be counting down and I wonder if it's related to the bores, the surface or the crankshaft.

When the engine was first made, the bores were measured and a number stamped next to the bore so that the person who installed the pistons could select the matching piston on the assembly line. Sometimes all of the bores have the same number but they can vary. The numbers have been crossed out when the engine was reconditioned I would suggest? Perhaps not all of the bores had work done on them.

Stephen

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[philthehill]

The numbers applied by BMC were placed within a diamond. All other forms of number are not BMC.

rocco
The fitment of a MG Metro camshaft was a common modification back in the day as was the 202 cylinder head.

[svenedin]

I too thought the numbers were in a diamond Phil but my engine has never been touched and the numbers are not in a diamond. Perhaps that is because my engine was made in 1969.

Stephen

[rocco]

Thanks to both of you for this, I'm learning so much every time I come on here - and I was told it was such a simple car!

I bought a replacement used camshaft yesterday on eBay, advertised as "like new" for an Austin Healey Sprite, MG Midget, Mini - 948, 1100 ccm. Comes with a pin-drive oil pump too which I don't think I need but it was a fair price for the two parts so impulsively as ever, I went for it. It's a 3D9, whatever that means.

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I measured the bores last night and got a few different readings, just over 62mm or 2.45 inches. I'll let the expert regrind the crank and bore out the cylinders and then I should have things evened up nicely.

[rocco]

I dropped the block, crank and pistons to the engineering place today. If I'm not mistaken then the cylinders can be bored one more time to 030, being that the stamp on the current big end bearings is 020, according to the book I have that says the 948cc block can be rebored three times, the 1098cc block only twice.

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[philthehill]

Do not believe all you read.
ESM sell 1098cc piston 0.040" oversize.
https://www.ebay.co.uk/itm/174081247484 ... R9rW_6m4Yw

[svenedin]

Do not believe all you read.
ESM sell 1098cc piston 0.040" oversize.
https://www.ebay.co.uk/itm/174081247484 ... R9rW_6m4Yw

They even go to +060" !!

https://www.morrisminorspares.com/engin ... -4-p830161

[rocco]

I finally got the nod to visit the engineers yesterday and it wasn't good news. The crankshaft recon will cost over €500 and block work (honing, surfacing, new distributor flange, fit camshaft bearings) more than €300.

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This is the dizzy flange that the drive spindle goes through and which is worn down by around 1mm. I can't find one at ESM but there is one on eBay (12A1136) - without an o-ring which will probably be just as difficult to source. It's listed for Minor 1000 models 1963-onwards but I'd love to know what the difference is between earlier engines. It looks the same as mine but knowing BMC they probably shaved or added a millimetre needelessly only to justify the jobs of their engine designers.

I'm going to hope the old engine I bought recently is in better nick and more serviceable when I pick it up but seeing this old thing from my engine, I'd like to replace it in any case.

[kevin s]

esm do a reground 948 crank and bearings for £200 if you return them.the old one.

[svenedin]

The earlier distributor housings did not have the O-ring and were prone to leaking oil. The later one is 12A1136 and can be found second hand. The o-rings are also available (13H2792).

Stephen

[rocco]

The earlier distributor housings did not have the O-ring and were prone to leaking oil. The later one is 12A1136 and can be found second hand. The o-rings are also available (13H2792).

Stephen

Top man. I just found that o-ring on eBay and snapped one up for €2.53 delivered!